A reputed member of the Genovese crime family once boasted that "I got a relationship . . . second to none" with former labor secretary Raymond J. Donovan's construction company, according to transcripts of FBI tape recordings made public today.

The remark about Schiavone Construction Co., where Donovan was executive vice president before he became a Cabinet member, came from William Pellegrino Masselli, a reputed Mafia soldier, on Jan. 23, 1979. He had just finished talking on the telephone with an executive of Donovan's company about how much business they might do together.

The transcripts represent the central evidence in the September 1984 indictment of Donovan and nine others on fraud and grand larceny charges. They also amount to a colorful preview of the prosecution's case at the forthcoming trial, set for Sept. 2.

The conversations suggest an intimate working relationship involving large amounts of money between Donovan's New Jersey-based firm and the company Masselli ran out of a Bronx warehouse. Masselli represented his company as a minority business controlled by a black state senator who, the tapes indicate, was a straw partner with no money and no power in the firm.

Neither Donovan nor his partner, Ronald Schiavone, is heard on the tapes.

The tapes also contain new details about Schiavone Construction's alleged scheme to obtain an extra $7.4 million from funds set aside for minority contractors on a $186 million Manhattan subway project. The method used, prosecutors charge, was for Masselli's firm, Jopel Contracting, to pretend to be renting and operating specialized tunnel-digging equipment that Schiavone actually owned and operated.

Masselli first discussed the plan after his Jan. 23, 1979, phone call with Albert J. Magrini, an officer of Donovan's company, the transcripts indicate.

"Now he's telling me, he wants to finance a million dollars worth of machinery," Masselli told a friend in his Bronx warehouse-office.

". . . They gotta give me 10 percent of the job . . . $18 million worth of subcontracting they have to give away. So they wanna give me as much as I can handle . . . . If they say they give it to us, they givin' it to a minority, and that helps them."

The 366-page transcript was filed with the clerk of the Bronx Supreme Court this morning in what Bronx prosecutors described as a partial response to a pending defense motion.

Defense attorneys protested the filing at a midday hearing, prompting Judge John P. Collins to order that one copy be submitted to him under seal and that District Attorney Mario Merola's office make efforts to retrieve the rest "forthwith."

"It's nothing but dirty pool and an attempt by the district attorney's office to disseminate these papers to the press," defense attorney Theodore Wells told the judge.

By then, however, copies had already been distributed by Merola's spokesman, Edward McCarthy.

The recordings include 28 conversations between Jan. 5 and June 28, 1979.

According to the transcripts, Masselli outlined how the firm that became Jopel began in the late 1970s as a joint venture with an old friend, Louis (Big Louie) Nargi. Masselli said he put up all the money, some $350,000, and got Nargi started on a subway job in Queens that Schiavone Construction had undertaken as general contractor.

Masselli said he got Nargi the excavating work through Patty Simonetti, son-in-law of the late Mafia boss Vito Genovese. "I got a relationship with Schiavone, second to none," Masselli declared. "We got a little connection with people in Jersey, with Patty."

Eventually, however, Masselli and Nargi had a falling out. Masselli took over the work under the name of Jopel Contracting, a firm he set up with Joseph Galiber, a black state senator from the Bronx, ostensibly serving as majority owner. The tapes show that Galiber put no money into the company and at one point was worried that no stock certificates were ever issued.

The transcripts include Masselli's end of phone conversations with some Schiavone executives and both ends of a May 10, 1979, chat with Schiavone vice president Joseph A. DiCarolis.

In the tapes, Masselli tells a friend that Schiavone would never have succeeded on its first subway job without his help. "Who do you think saved 'em with the unions?" Masselli said. "We saved 'em with the . . . unions and everything over there . . . . "

On a March 10, 1979, tape discussing mining equipment for the subway job, Masselli recounted a conversation with a Schiavone executive named "Joe."

Masselli said he was told that "we're going to run the equipment through your company," but "they want to take the tax write-off on it" as well.

"Their lawyers and accountants are getting together to see how they could do it," Masselli said. "They want the write-off, but they also want that the million dollars counts toward the, the 10 percent [minority business requirement].

"I said, 'Joe, you work it out,' " Masselli recounted. Masselli also indicated he was supposed to receive $75,000 for the arrangement.

"I says, 'With me, you could go to sleep, you don't have to worry,' " Masselli said. "That's what he likes. And he wants some green back, you know . . . . "

One of nine men awaiting trial with Donovan, Masselli is currently in prison for truck hijacking and drug trafficking. He has also been accused of murder in the 1978 killing of Salvatore (Sally Blind) Frascone, a reputed member of the Bonanno crime family.